Body fluid flow control device

ABSTRACT

An implantable apparatus and a method for controlling fluid flow within a host body, for example for use as an incontinence device. A constricting member is provided for reducing fluid flow within a body canal when in a closed position, and for allowing fluid flow within the body canal when in an open position. In addition, there is a control mechanism for controlling movement of the constricting member between said open and closed positions. A link member links the constricting member and the control mechanism such that the constricting member and the control mechanism are implantable in different parts of the host body. A coupling for selectively transmitting axial movement to the link member may be provided between the link member and the control mechanism so that the constricting member cannot apply a damaging amount of force to the body canal.

Cross-reference to related applications This is a continuation-in-partapplication of copending U.S. patent application number 09/676,336,filed Sep. 29, 2000. FIELD OF THE INVENTION

[0001] The invention relates to an implantable medical device and amethod for the control of fluid flow through a body host canal orvessel, such as a urethra.

BACKGROUND

[0002] Incontinence is a condition wherein persons lose control overtheir voluntary urinary function. The condition can arise from variouscauses, which include a variety of related and unrelated diseases,aging, and deterioration of the voluntary urethra sphincter muscle. Thecost and inconvenience to persons suffering from this condition aregreat. Several remedies exist that are known in the prior art. Amongthese, the most common are surgical corrections both minor and major,drugs, devices and diaper capture systems which serve to capturedischarges. Another solution is to place a patch over the urinaryorifice to prevent unwanted discharge. Possibly, the most effectivesolution to date is the use of an artificial sphincter. This device issurgically installed and is hydraulically or pneumatically driven,operating by inflation of ballasts to suppress fluid flow. However,control of this device is sometimes difficult and is often inconvenient.Throughout the full range of the available treatment alternatives, thelevels of efficacy, useful life, and complications vary greatly, withnone of the current treatment alternatives being particularly effectivein especially severe cases. Accordingly, there is a need for an improvedapparatus to control the loss of voluntary urinary function.

SUMMARY OF THE INVENTION

[0003] The present invention overcomes and alleviates theabove-mentioned drawbacks and disadvantages in the art through novelimplantable body fluid flow control devices for the control of fluidflow through a host body canal or vessel, such as a urethra.

[0004] Generally speaking, and in accordance with a first aspect of theinvention, an implantable apparatus for controlling fluid flow within ahost body comprises a constricting member for allowing fluid flow withina body canal when in an open position and for reducing fluid flow withina body canal when in a closed position, an actuating member foroperating the constricting member between said open and closedpositions, and control means for operating said actuating member.

[0005] Preferably, the constricting member comprises a first engagingelement and a second engaging element for coupling to the first engagingelement to encircle a body canal. At least one of the first engagingelement and the second engaging element preferably has apertures toallow tissue growth therethrough from and to the surface of the bodycanal. A locking member is preferably provided for locking the firstengaging element and second engaging element into the locked position.

[0006] The constricting member preferably comprises a plunging membermoveable such that the plunging member may apply pressure against saidbody canal to compress said body canal into said closed position. Theactuating member preferably comprises a connector having first andsecond ends. The first end of the connector is preferably attached tosaid plunging member and is axially moveable by said control means tomove said plunging member.

[0007] The actuating member may comprise a housing whereby the secondend of the connector extends slidably through an aperture in the housingand is coupled to an actuator provided in the housing, for examplephysically or by way of magnetic fields, such that movement of theactuator results in movement of said plunging member away from the bodycanal to allow at least some fluid flow therethrough. The actuatingmember preferably comprises a motor operatively coupled to the secondend of the connector so that activation of the motor causes the secondend of the connector to be axially pulled towards the motor resulting inmovement of said plunging member away from the body canal to allow atleast some fluid flow therethrough.

[0008] A trigger mechanism is preferably provided for activating themotor. The trigger mechanism may be a magnetically operated switch, aradio-controlled circuit, a manually operated button implanted under thepatient's skin, or any other suitable trigger mechanism. A manualoverride system may also be included. The manual override system mayinclude a magnet that can be used outside the patient's body.

[0009] A second aspect of the invention provides an implantableapparatus for controlling fluid flow within a host body comprising aconstricting member for restricting fluid flow within a body canal whenin a closed position, and for allowing fluid flow within the body canalwhen in an open position; a control mechanism for controlling movementof the constricting member between said open and closed positions; and alink member linking the constricting member and the control mechanismsuch that the constricting member and the control mechanism areimplantable in different parts of the host body.

[0010] The control mechanism can be separable from said link member sothat said control mechanism may be replaced without removal of theconstricting member or the link member from the host body.

[0011] Preferably, the link member is adapted for moving saidconstricting member between said open and closed positions so as toalter fluid flow within the body canal, and an actuating member ispreferably provided for actuating said link member. The link member maybe a cable provided in a protective sleeve, or may be any other suitablelink between the constricting member and the control member such as awire carrying electronic control signals, a wireless radio communicationsystem, etc.

[0012] The actuating member and the control mechanism are preferablyprovided in a housing separate from the constricting member. Theactuating member is preferably a motor, most preferably with a remotelyoperated trigger mechanism, for example, a magnetically operated triggermechanism, for activating the motor or magnetic unit from a positionoutside the patient's body.

[0013] The motor or magnetic unit preferably acts through a worm gear.Preferably, the worm gear defines an axis, and the link member isattached to a casing, the worm gear co-operating with a threadedaperture provided in said casing in order to move said casing in adirection parallel to the axis of the worm gear.

[0014] According to another aspect of the present invention, there isprovided a seal for an elongated link member, the link member extendingbetween an implantable apparatus for implantation in a host body and acontrol mechanism. The link member extends through an opening in ahousing. The seal includes a tubular membrane having two openings, oneopening being sealed to the housing, the other opening being sealed tothe link member such that fluid entering the housing around the linkmember is trapped by the membrane. The membrane flexes to allow movementof the shaft.

[0015] The membrane is preferably sealed to said link member by grippingmeans extending around the membrane and the shaft. The gripping meansmay comprise a coil. The membrane preferably comprises a bellows thatfolds inwardly when the link member is moved axially away from aninterior of the housing, and expands when the link member is movedaxially into the housing. The bellows may include a reinforcing ring sothat folding of the bellows may be controlled.

[0016] According to yet another aspect of the invention, there isprovided an operating mechanism for a constricting member forcontrolling fluid flow in a body canal. The constricting member isactuable between open and closed positions. The operating mechanismincludes an axially moveable link member operatively connected to theconstricting member for actuating the constricting member. Operatingmeans are provided for axially moving the link member. A coupling forselectively transmitting the axial movement is connected between thelink member and the operating means.

[0017] The coupling acts so that in one direction there is positiveengagement between the operating means and the link member, whereas inan other direction, some play is allowed between the operating means andthe link member. The coupling may be used so that opening of the bodycanal may be achieved by direct actuation of the operating means actingon the link member, but on closing of the body canal, the couplingprevents pressure being directly applied to the body canal by theoperating means, thus reducing the likelihood of damage to the bodycanal.

[0018] The coupling may include magnets or a compressible member. Amagnet may be attached to the link member, and at least one other magnetmay be attached to the operating means. The magnets may be physicallymoveable towards and away from each other, or they may be electromagnetssuch that they may be operated when required. The compressible membermay be provided in a moveable casing. The link member may be operativelyconnected to the compressible member, the motor acting to move thecasing, and the compressible member acting to move the link member.Alternatively, the coupling may include chain links or anointedextensible framework, or other means of preventing direct application ofpressure to the body canal.

[0019] In the case of a coupling comprising magnets, a manual overridesystem may be included, which manual override system comprises a furthermagnet operable from outside the patient's body. The manual overridemagnet should be of sufficient strength to move the magnet attached tothe link member against the magnetic force of the magnet attached to theoperating means.

[0020] Another aspect of the invention provides a method of controllingfluid flow within a host body. The method includes implanting aconstricting member around a body canal, the constricting memberreducing fluid flow in the body vessel when in a closed position. Themethod further includes implanting a control mechanism in the host body;and providing and implanting a link member between the constrictingmember and the control mechanism to allow the control mechanism tocontrol the constricting member. The control mechanism may be removedfrom the host body and replaced without removal of the constrictingmember and the linking member.

[0021] The constricting member may include engaging elements defining anopening therebetween, the method including surrounding the body canalwith the engaging elements so that the body canal extends through theopening.

[0022] The method may further include suturing the engaging elements tothe vessel. In addition, the control mechanism may be implanted remotefrom the body canal.

[0023] Yet a further aspect of the invention includes a remote telemetrysystem for an implantable apparatus, the telemetry system including asignaling mechanism capable of sending and receiving signals to and froma control unit implanted in a host body in order to monitor theoperation of the implantable apparatus, the telemetry system beingcapable of altering operating settings of the implantable apparatus.

[0024] The signals are preferably electromagnetic radiation, mostpreferably radio signals. The implantable apparatus may include sensorsto monitor actions of the implantable apparatus on the host body, andthe telemetry system would include a mechanism to interrogate thesensors to provide feedback on the sensed data. Preferably, the sensorsare capable of monitoring pressure exerted by a moveable part of theimplantable apparatus on a part of the host body, the feedback on thesensed data including commands to alter the range of movement of themoveable part of the implantable apparatus.

[0025] Another aspect of the invention includes an implantable apparatusfor controlling fluid flow in a host body. The implantable apparatusincludes a constricting mechanism including a reciprocable member forselectively applying pressure to a canal of the host body in order toselectively constrict the canal. A pressure sensor is included fordetecting the pressure applied by the reciprocable member to the canal.A feedback system is also included for altering movement of saidreciprocable member in response to the pressure sensed by said pressuresensor in order to prevent damage to said canal.

[0026] The object and advantages of the implantable fluid flow controldevices of the present invention permit implantation and use withoutsevering the canal or vessel to be constricted. Moreover, because traumais minimized with respect to the canal or vessel, and the devices of thepresent invention are relatively small, lightweight and made ofcorrosion-resistant material, such as durable plastics, titanium orstainless steel, the devices are suitable for use for extended periodsof time to control fluid flow through numerous types of vessels tocontrol, for example, urination, defecation, ejaculation, nutritionabsorption for control of obesity, etc. Splitting the fluid flow controldevice and its control box also provides significant advantages. Thesurgery to implant the fluid flow control device is delicate andinvolved, whereas the surgery to implant the control box is much lessinvolved as the control box may be implanted in an easily accessibleplace, just under the skin of the patient. Thus, when any part of thecontrol box fails, the control box may be removed and replaced with anew control box without needing to adjust the fluid flow control device.The replacement of the control box does not therefore need to be done bya specialist surgeon, and may be performed in a large number ofhospitals or even physicians offices under local anaesthetic. Thesurgery is thus much less traumatic for the patient and may be performedin a location that is convenient for the patient rather than in ahospital that is able to perform specialized urological surgeries.

[0027] These and other objects, features and advantages of the presentinvention may be better understood and appreciated from the followingdetailed description of the embodiments thereof, selected for purposesof illustration and shown in the accompany drawings. It should thereforebe understood that the particular embodiments illustrating the presentinvention are exemplary only and not to be regarded as limitations ofthe present invention. In particular, the illustrated embodiment relatesto an artificial sphincter for a urethra, but it should be understoodthat the device can be used with any body fluid flow canal or vessel.

Brief Description of the Drawings.

[0028] The foregoing and other objects, advantages and features of thepresent invention, and the manner in which the same are accomplished,will become more readily apparent upon consideration of the followingdetailed description of the present invention taken in conjunction withthe accompany drawings which illustrate a preferred and exemplaryembodiment, and wherein:

[0029]FIG. 1 is a front exploded view of a body fluid flow controldevice according to the invention;

[0030]FIG. 2 is a side exploded view of the body fluid flow controldevice of FIG. 1;

[0031]FIG. 3 is a partial side view of the device of FIG. 1 in theclosed position;

[0032]FIG. 4 is a partial front view of the device of FIG. 1 in theclosed position;

[0033]FIG. 5 is a side exploded view of a control box and device for usewith a body fluid flow control device;

[0034]FIG. 6 is a partial top view of the control box and device of FIG.5;

[0035]FIG. 7 is a partial cross-sectional view of a motorized activatingmember for use with the device of FIG. 1 in the open position;

[0036]FIG. 8 is a partial cross-sectional view of the motorizedactivating member of FIG. 7 in an intermediate position;

[0037]FIG. 9 is a partial cross-sectional view of the motorizedactivating member of FIG. 7 in the closed position;

[0038]FIG. 10 is a top partial cross-sectional view of an alternativeembodiment of control box and device;

[0039]FIG. 11 is an enlarged cross-sectional view of the joint betweenthe cable and link member of FIG. 10;

[0040]FIG. 12 is a partial cross-sectional view of an alternativeembodiment of motorized actuating member;

[0041]FIG. 13 is a top partial cross-sectional view of yet a furtheralternative embodiment of control box and device;

[0042]FIG. 14 is a partial cross-sectional view of the control device ofFIG. 13;

[0043]FIG. 15 is a partial cross-sectional view of an alternative meansof connecting a link member to a body fluid flow control device; and

[0044]FIG. 16 is a partial cross-sectional view of a further alternativemeans of connecting a link member to a body fluid flow control device.

Detailed Description of the Invention

[0045] By way of illustrating and providing a more complete appreciationof the present invention and many of the attendant advantages thereof,the following detailed description is given concerning the novelimplantable body fluid control device and uses thereof.

[0046] Referring now in more detail to the drawings, in which likenumerals refer to like parts throughout several views, FIGS. 1-4 show abody fluid flow control device according to the present invention. Thebody fluid flow control device comprises a first engaging element 102and a second engaging element 104. When the first engaging element 102is coupled with the second engaging element 104, an inner diameter isformed which is suited for fitting around a host body canal, i.e., anytube or vessel V within the human or animal body, such as the urethra.

[0047] The body fluid flow control device also comprises a lockingmechanism 106 for locking the first and second engaging elements 102 and104 together. The locking mechanism 106 may be of any suitable form. Inthe illustrated embodiment, locking mechanism 106 is in the form oflocking pins 108 located on the first engaging element 102 and lockingholes 110 located on the second engaging element 104. In the illustratedembodiment, two locking holes 110 are provided on each side of engagingelement 104. Each locking pin 108 is capable of being attached to eitherof the locking holes 110. The inner diameter formed between parts 102and 104 may thus be adjusted for use with different sized vessels. Itshould be understood that any other equivalent locking mechanism can beused for this purpose. Alternative locking mechanisms contemplated bythe present invention include, but are not limited to, the use of astrap and snap pins or interconnecting molding on the first and secondengaging elements 102 and 104.

[0048] The body fluid flow control device of the present inventionpreferably further includes a piston-like or plunging member 112 locatedwithin the inner diameter formed by the coupling of the first and secondengaging elements 102 and 104 such that the plunging member 112 mayapply pressure against a body canal or vessel, such as a urethra. As canbe seen most clearly from FIGS. 2 and 15, plunging member 112 may have acurved profile such that only outer edges of the plunging member contactthe vessel surface in use. This substantially reduces the likelihood ofnecrosis of the tissue of the vessel because it allows pressure to beplaced on the vessel over a smaller area than would be possible with aflat plunging member. The curved profile of plunging member 112 may beprovided on a removable plunger head, so that a surgeon may select anappropriately sized plunger head for the size of the vessel.

[0049] It should be appreciated that the fluid flow control device maytake other forms than that illustrated. For example, instead of aplunging member provided in two engagement members, one of theengagement members could be moveable with respect to the other tocompress the vessel in order to restrict fluid flow therein.Alternatively, a fluid flow control device in the form of an artificialexternal annular sphincter or other means for compressing the vessel maybe applied to the vessel.

[0050] Apertures 113 may be provided in first engaging element 102. Theapertures 113 permit tissue growth therethrough from and to the surfaceof the vessel in order to anchor the body fluid control device onto thevessel. Further apertures (not shown) may be provided to allowdissolvable sutures to be used to secure the engaging element to thevessel on a temporary basis, until the engaging element is completelyanchored in place by the tissue growth. Alternatively, the material ofthe engaging element may be such as to allow suturing therethrough, orthe engaging element may be otherwise attached to the vessel. It hasbeen found that tissue growth is achieved within a few weeks ofimplantation of the device into a host body and so it may also bepossible to implant the device without any form of attachment to thevessel, and to simply let the tissue growth firmly attach the device tothe vessel over time.

[0051] All components of the device are made from biologically inert andcompatible materials. For example, the fluid flow control device may bemade of polypropylene, silicone, titanium, stainless steel and/orTeflon.

[0052] An actuating member is utilized by the body fluid flow controldevice of the present invention to bias the plunging member 112 to applypressure against the body vessel when the body fluid flow control deviceis in the closed position, and to pull the plunging member 112 away fromthe vessel to open the device. The actuating member may comprise a cable114 covered by a protective sleeve or sheath 116, the cable 114 having afirst end 118 and a second end 120. Cable 114 is preferably a braidedstainless steel cable, although any suitable material may be used.Protective sleeve 116 is preferably made from a bio-compatible materialhaving non-stick properties to discourage tissue growth thereon. Asuitable material is Teflon. The cable 114 may be slidably moveablewithin sleeve 116, or cable 114 and sleeve 116 may be slidably moveabletogether.

[0053] The first end 118 of the cable 114 runs slidably through anaperture (not shown) in the second engaging element 104 and is attachedto the plunging member 112. A collar 122 is provided around the sleeve116 where it passes through the aperture in the second engaging element104, in order that any tissue growth on and around second engagingelement 104 does not interfere with the movement of sleeve 116 throughthe aperture, if the sleeve 116 is designed to move with cable 114. Ifcable 114 is slidably moveable within sleeve 116, collar 122 preventstissue ingress into the end of sleeve 116.

[0054]FIGS. 5-9 illustrate a control box for the fluid flow controldevice that is connected to end 120 of cable 114. The control boxcomprises a housing 202, a motor 204 having a worm gear 206, a spring208 and bellows 210 to provide a seal around sleeve 116. The housing 202may be made of polypropylene or any other suitable biologically inertmaterial. Batteries 212 are also provided, which should preferably besuitable for implantation in the body, such as batteries manufactured byWilson Greatbatch Ltd, of Clarence, N.Y., USA. An operating mechanism(not shown) may be provided in the control box, or may be implantedseparately in the host body in an easily accessible place.

[0055] The arrangement of the control box and cable 114 allows thecontrol box to be implanted in the body separately from the fluid flowcontrol device. For example, the control box may be implanted close tothe patient's skin in their abdomen, with the cable 114 and sleeve 116extending from the control box 202 to the fluid flow control device thatis implanted around the urethra or other body vessel.

[0056] Cable 114 is attached at end 120 to a nut 216 which is located inthe interior of a slidably moveable casing 214 in housing 202. Spring208 is also located within casing 214, which has a threaded aperture 218to allow worm gear 206 to pass into the interior of casing 214.

[0057] Spring 208 is interposed between the motor 204 and cable 114 inorder to provide a coupling for selectively transmitting axial movementfrom the motor 204 to the cable 114 and hence to the body vessel V, theoperation of which is described with reference to FIGS. 7 to 9 below. Inthe illustrated embodiment, the motor 204 acts on casing 214 to movespring 208 and cable 114 by means of the nut 216. However, any suitablecompressible member may be used in the casing 214 to cushion the vesselfrom the action of the motor, for example, a resiliently deformablematerial may be used, or a compressible fluid such as a gas could beused if casing 214 was suitably sealed. Alternatively, a spring or othercompressible member may be connected directly to or inserted in cable114. Such an arrangement would preferably use a compressible member thatwas stiff enough so that pushing and pulling motions were still impartedto the cable 114 on operation of the motor.

[0058] The slidable casing 214 and worm gear 206 allow axial movement tobe imparted to cable 114 by motor 204, but it should be appreciated thatany suitable axial actuation of cable 114 may be used. For example, themotor 204 may have an axially moveable actuator, or suitable gearingcould be provided to act on a toothed rack or other axially moveableelement. Alternatively, the cable could have a flexible end that may bewound around an axle in housing 202.

[0059] The sleeve 116 containing cable 114 should be sealed to housing202 to prevent ingress of body fluids from damaging the motor and othercomponents of the control box. Any suitable seal may be used, but itshould be noted that where sleeve 116 is designed to be slidablymoveable, it is not possible to seal tightly around sleeve 116, as thesleeve needs to be axially moveable in order to impart movement toplunging member 112. One method of sealing sleeve 116 to housing 202 isto use a bellows mechanism. A suitable bellows mechanism 210 isillustrated in FIGS. 7-9. Bellows 210 is designed so that as sleeve 116moves axially, bellows 210 expands or collapses in on itself so thatfluid that seeps into housing 202 around sleeve 116 is captured bybellows 210, and can be forced back out of the housing 202 when thedevice is moved to a closed position.

[0060] The sleeve 116 may be sealed to bellows 210 and housing 202 bymeans of a threaded bolt 220, and a nut 222. Bolt 220 is passed throughan aperture in housing 202 with its head 224 in the interior of thehousing. Sleeve 116 passes through and is a close fit with a centralbore 226 in bolt 220. Bellows mechanism 210 is generally tubular and issealed to the underside of head 224 of bolt 220 by an O-ring seal 228.As the nut 222 is tightened on bolt 220, compression of the O-ring seal228 causes a tight seal to prevent ingress of fluid into housing 202around the exterior of bolt 220. Bellows 210 extends around the head 224of bolt 220 and is sealed to sleeve 116 in the interior of housing 202by a tightly wound spring 230. The spring 230 may be placed onto thebellows 210 before the sleeve 116 is forced through the bellows 210 andspring 230 in order to obtain the tightest seal possible. Other methodsof sealing bellows 210 to sleeve 116 include cable clamps, C-clips,adhesive, etc. A reinforcing ring 234 is provided on one surface ofbellows 210, to ensure that the bellows 210 collapses correctly as thesleeve 116 is moved axially. The reinforcing ring 234 may be a thickenedarea in the wall of the bellows 210, or may be a separate ring that isattached to the bellows, by gluing or any other suitable means. Instead,or in addition to, the reinforcing ring 234, the bellows may be pleatedor folded in order to ensure correct folding when the fluid flow controldevice is moved to the closed position.

[0061] It should be noted that bellows 210 can be of any suitable shape,provided that a seal is made at the housing and around the sleeve, andthat bellows allows movement of the sleeve into and out of the housing.For example, bellows 210 may be a simple tubular shape, with ends of thetube being sealed to the housing and sleeve. Alternatively , bellows 210may be of a frusto-conical shape, or a more complicated shape such as abell-shape or could be folded or pleated. The seal to the housing couldbe close to the aperture in the housing through which the seal extends,as illustrated, either inside the housing or outside the housing.Alternatively, the seal could be made to the wall of the housing, aroundor behind the bolt 220.

[0062] It is possible to seal the sleeve 116 and the housing 202 withoutusing a bellows mechanism, but it has been found that energy losses arecreated as movement of the sleeve 116 creates friction against the seal.This can cut the battery life of the motor by up to ⅓. For example, aflexible annular ring may be sealed between the sleeve 116 and thehousing 202, the annular ring stretching as the sleeve is axially moved.Alternatively, a series of seals may be provided along sleeve 116, eachseal preventing some fluid ingress to housing 202.

[0063] Control circuitry (not shown in FIGS. 7-9) is provided, whichoperates the motor on receipt of a signal from an operating mechanism.Any of the several well-known control devices can be used to control theoperation of the body fluid flow control devices of the presentinvention by a user so long as the objectives of the present inventionare not defeated. Suitable operating mechanisms include radio-controldevices, or a magnetic devices that can be sensed by the controlcircuitry. With a magnetic device, the user may be provided with aseparate magnet that they carry with them, and which they positionadjacent the skin over the implanted switch when they wish to operatethe device. The magnet may be of any suitable shape, and may be shapedfor example like a pen or credit card so that its purpose is notimmediately apparent to other people. The magnet should have a weakmagnetic field so that it must be placed close to the switch in order tooperate the device, in order to prevent accidental operation of thedevice if the magnet is carried in a pocket. Alternatively, a touchsensor, infrared, voice or sound activation may be used, or a manuallyoperated switch may be implanted under the skin of the patient.

[0064] A remotely operated operating mechanism is preferred because thedevice can be operated without irritation to the skin, as would happenwith a manually operated trigger. In the preferred embodiment, a manualoverride switch may be provided in addition to the remotely operatedtriggering mechanism. The manual override switch is designed to be usedtemporarily if the control box fails and the user is not close to aphysician's office or hospital to have the control box changed. Themanual override switch may be provided in the control box, and may besealed from the interior of the control box until the first activationof the switch, for example by a membrane seal. Such a use of the manualoverride switch may eventually allow fluid ingress into the control box,which may then need to be replaced. Alternatively, no manual overrideswitch may be provided, which would mean that the user would have to useincontinence pads until the control box could be replaced.

[0065] The control circuitry controls operation of the motor, and maydetect the position of the plunging member, for example, via theposition of the casing or via the drag exerted on the motor. Preferably,the control circuitry also monitors the level of charge in the battery.The control circuitry can be used to initiate opening or prevent closingof the fluid flow control device if a problem such as low battery or adefective motor is detected, so that the device can be caused to remainin the open position. For example, once the device has been opened, anabutment (not shown) may be caused to contact the casing 214 to preventany further movement thereof. The motor may also be shut off. The devicemay still be operable by a manual override, as the spring 208 can becompressed and allowed to expand within casing 214 to allow movement ofthe cable 114 to open and close the device.

[0066] The control box 202 may also contain components that allow aphysician to interrogate the control circuitry by a remote telemetrysystem without accessing the box itself. Such components may beinterrogated and/or controlled by radio waves or other interactivesignals transmitted and received by the telemetry system, or any othersuitable mechanism. This allows the physician to check the charge in thebatteries, any internal sensors, to alter the tension in the cable 114,and to make other suitable adjustments. A pressure sensor may beprovided on the plunger 112 to monitor the pressure between the plunger112 and the vessel V when the plunger is in the closed position. Thepressure sensor may also be interrogated by the telemetry system, whichcan then be used to alter the settings for the control device. Forexample, the number of turns that the motor 204 causes worm gear 206 tomake on each operation of the device may be altered in order to set thecorrect distance of travel of the cable 114, and hence plunger 112 forany particular patient so as to alleviate any excess pressure exerted onthe vessel V. In addition, the telemetry system may include controlcommands to cause the motor to open and close the body fluid flowcontrol device, either as an override system to the normal operatingmeans, or in addition to the normal operating means in order to test thedevice in situ.

[0067] If the control box causes the device to fail or remain in theopen position if a problem is detected, this will simply mean that thepatient will return to the condition that they were in beforeimplantation of the device, in other words, in a condition ofincontinence. If the device failed in the closed position, the patientwould need to be catheterized. However, a manual override system wouldallow the patient to operate the system manually for a considerableperiod of time or until medical aid was obtainable.

[0068] Actuation of the device is described with reference to FIGS. 7 to9. In the open position shown in FIG. 7, the motor 204 has operated theworm gear 206 to draw casing 214 towards the motor 204. This pulls nut216 along with the casing 214, and thus acts on cable 114 to pull theplunging member 112 away from the vessel V. Bellows 210 is also at itsfully extended position. In order to close the fluid control device, themotor 204 is activated to turn worm gear 206 in the opposite directionto that used to open the device. As worm gear 206 is operated, casing214 is moved away from the motor 204, spring 208 pushing on nut 216 tobias plunging member 112 against the vessel V, as shown in FIG. 8. Asthe motor 204 is operated further, the vessel V prevents plunger 112moving, and prevents movement of cable 114 and hence nut 216, due to theincreased force needed to move cable 114 against the vessel V when thevessel V is already closed. Nut 216 presses against spring 208, causingcompression of the spring 208, as shown in FIG. 9. It can thus be seenthat any further movement of worm gear 206 by motor 204 does not resultin compression and injury of the vessel V, but the further compressionof spring 208. In this way, axial movement of casing 214 may beselectively transmitted to cable 114. This protects the vessel V againstfailure of the device by continuous running of the motor 204, as thevessel cannot be further compressed due to the interplay between thevessel V and the spring 208.

[0069] An alternative embodiment of the control box is illustrated inFIGS. 10 and 11. The control box comprises a housing 902, a motor 904having a worm gear 906, a spring 908 and bellows 910. Batteries 912 arealso provided, along with control circuitry (not shown). The spring 908is located in a slidable spring casing 914. An operating mechanism (notshown) may be provided in the control box, or may be implantedseparately in the host body in an easily accessible place. The spring,worm gear and motor arrangement are as described for FIGS. 5-9, and willnot be further described.

[0070] Housing 902 is preferably formed in two pieces, a main body 916and an end lid 918. End lid 918 includes a lip 920 that fits inside anend 922 of main body 916. A groove 924 is provided around lip 920, inorder to receive an O-ring 926. End lid 918 is also sonically welded tomain body 916 in order to provide a good seal. A groove 928 is providedaround the exterior of end 922 of main body 916, in order to allow forease of removal of lid 918 with a suitable tool when necessary. Aninterior housing 930 extends along the length of housing 902, to oneside thereof, in order to separate the motor 904, worm gear 906,slidable casing 914, bellows 910 and other moveable parts from thebatteries 912. Interior housing 930 has a flange 932 at an end 934remote from end 922 of main body 916, with an O-ring groove 936 providedin flange 932. A set screw 938 is also provided in interior housing 930,in order to lock motor 904. Electrical contacts 940 extend to motor 904from end lid 918. An internally directed collar 942 having an internalthread extends around flange 932 within housing 902, and interiorhousing 930 is secured into housing 902 by means of an externallythreaded nut 944 which is screwed into place to hold flange 932 inposition. Nut 944 may have pin holes 946 to allow for tighteningthereof. An externally directed collar 948 having an internal thread isalso provided in housing 902, in order to allow the cable 114 to passinto interior housing 930.

[0071] Sleeve 116 has an end 950 which is attached to a hollow connector952 having a first end 954 and a second end 956. At end 954, connector952 has backwardly-directed teeth 958 around the circumference thereofwhich attach to the inside of sleeve 116 adjacent to end 950, and act toprevent sleeve 116 from being pulled loose. The second end 956 ofconnector 952 has an external thread 960, as well as a groove 962suitable for receiving an O-ring 964. Thread 960 is screwed into theinternal thread provided within collar 948 on housing 902. Cable 114extends into housing 902 through connector 952, and is attached at itsend 120 to a link member 966 which extends into casing 914 andterminates in nut 216. The connection between cable 114 and link member966 is shown enlarged in FIG. 11. The cable end 120 is fitted into aconnector piece 968 that has a tapered end 970 and a groove 972 forreceiving a sealing ring. Link member 966 has an opening 974 forreceiving connector piece 968, opening 974 having an internal shoulder976. A metal O-ring 978 is received by shoulder 976 and is held in placeby a ring retainer 980. Connector piece 968 is pushed into opening 974until the metal O-ring 978 seats in groove 972 to form a seal betweenconnector piece 968 and link member 966.

[0072] Bellows 910 are attached to housing 902 by means of nut 944screwed into inwardly directed collar 942. Bellows 910 has an end flange982, which extends adjacent to flange 932 of interior housing 930, andhas an integral O-ring 984 to seal in O-ring groove 936 of flange 932 sothat bellows 910 is tightly sealed to housing 902 by interior housing930. Bellows 910 is also attached to cable link member 966 by means of acable link 986, and has a pleated conical shape above flange 982 so thatit may fold easily when compressed. It should be noted that in theembodiment of FIG. 10, the bellows 910 is not attached to the sleeve116, as the sleeve 116 is not axially moveable. Instead, cable 114 isaxially moveable within sleeve 116. In this embodiment, bellows 910 maynot be necessary, as a good seal may be provided between connector 952and control box 902. However, it is advantageous to provide anadditional seal, for example using bellows 910, to prevent fluid ingressinto control box 902.

[0073] The operation of the control box of FIG. 10 is the same as forthe control box of FIGS. 5 to 9, and will not be further described.

[0074] A further alternative embodiment of a seal for the sleeve and anactuator for the cable is illustrated in FIG. 12. In the illustratedembodiment, control box 1200 is completely sealed so that no fluidingress into the box can take place. A hollow cylindrical bore 1202 thatis sealed at one end 1204 is formed in control box 1200. Bore 1202 hasinternal threads 1206 provided adjacent an outer surface of control box1200.

[0075] An end of sleeve 116 is attached to a hollow connector 1208,connector 1208 having an end 1210 and an end 1212. End 1210 of connector1208 is dimensioned to pass into the end of sleeve 116, connector 1208having outwardly and rearwardly directed teeth 1214 at end 1210 toengage the interior of sleeve 116, thereby securing connector 1208 tosleeve 116. End 1212 of connector 1208 is dimensioned to be slightlylarger in diameter than sleeve 116, and has external threads 1216.Connector 1208 may be screwed into bore 1202 of control box 1200 bymeans of threads 1216 and 1206.

[0076] End 120 of cable 114 is located in bore 1202, and is providedwith a collar 1218. An annular magnet 1220 is supported by collar 1218around end 120 of cable 114. Cable 114 is axially moveable within sleeve116, and therefore a bellows seal is not necessary around sleeve 116. Inaddition, as sleeve 116 is not moveable, tissue growth around the sleevecannot affect the operation of the device.

[0077] A motor 1222 has a threaded worm gear 1224 engaged with a casing1226 through a screw-threaded aperture 1228 located in the bottom of thecasing. Casing 1226 extends around bore 1202, and an annular magnet 1230is supported around the interior of an upper edge of casing 1226. Magnet1230 is aligned with magnet 1220 located on end 120 of cable 114.

[0078] In order to actuate cable 114 to open and close the fluid flowcontrol device, the motor 1222 operates the worm gear 1224, which movescasing 1226 along the exterior of bore 1202. Magnet 1230 acts throughthe plastic material comprising bore 1202, and causes magnet 1220 totrack its movement. This in turn causes cable 114 to be axially moved,operating the fluid flow control device. If the motor 1222 continuesoperating the worm gear 1224 towards the cable 114 when the body vesselhas already been closed, the attraction of magnet 1220 for magnet 1230is not enough to cause the cable 114 to be moved further, due toresistance from the vessel walls, thus preventing potential damage tothe vessel. Thus, axial movement of casing 1226 is selectivelytransmitted to cable 114. In addition, the casing 1226 will come to restagainst bore 1202 or an interior surface of control box 1200, preventingthe magnets from getting too far out of alignment.

[0079] It should be appreciated that a magnetic link between the motorand cable may be achieved in many ways other than that illustrated inFIG. 12. For example, the magnets need not be annular, but could beplaced to one side of the cable. In addition, the magnets need notoperate by mutual attractions, but could work by repelling each other toclose the vessel, with a spring action or other means operating to openthe vessel once the motor-driven magnet was pulled back towards themotor. With a repelling action, magnets could be placed directly on theends of the cable and an axially movable actuator driven by the motor.

[0080] An alternative embodiment of a magnetic coupling for selectivelytransmitting axial movement to the cable is illustrated in FIGS. 13 and14. These figures illustrate a control box 1300 that is completelysealed. A bore 1302 having a blind end 1304 is provided in the controlbox 1300 for receiving the end 120 of cable 114. A connector 1306 isused to connect sleeve 116 to bore 1302. The connector 1306 has a firstend 1308 with rearwardly directed teeth 1310, a central shoulder 1312and a second end 1314 having external screw threads 1316. End 1308 ofconnector 1306 is pushed into the end of sleeve 116, the teeth 1310acting on the inner surface of the sleeve. End 1314 of connector 1306 isconnected to control box 1300 by means of an O-ring seal 1318 and aninternally threaded nut 1320 which is threaded onto threads 1316. Nut1320 is welded at 1322 to the control box 1300 to form a tight seal.

[0081] The cable 114 extends into bore 1302. A cylindrical magnet 1324is attached to end 120 of cable 114 by a collar 1326 which is deformedonto the magnet 1324 and cable end 120 for a tight fit. The control box1300 includes a motor 1328, a worm gear 1330 and batteries 1332 asdescribed for the FIG. 10 embodiment. A casing 1334 having an annularmagnet arrangement 1336 is threaded onto worm gear 1330, and operates inthe same manner as in the FIG. 10 embodiment so will not be furtherdescribed. Control circuitry including IC's 1338 and other standardcomponents 1340 including resistors and capacitors are also shown.

[0082]FIG. 15 illustrates an embodiment of a connector joining first end118 of cable 114 to the body fluid control device. Connector 1500 has afirst end 1502 having outwardly directed teeth 1504 which grip into theinner surface of sleeve 116. A second end 1506 of connector 1500 has acollar with inwardly directed threads 1508 which are threaded ontooutwardly directed threads 1510 on a collar 1512 attached to the bodyfluid flow control device. An O-ring 1514 forms a tight seal to thecollar 1512.

[0083]FIG. 15 also illustrates plunger 112 in detail. Plunger 112includes a perforated metal bracket 1516 attached to a metal collar1518. The main body of plunger 112 is formed of silicon that is moldedonto the perforated bracket 1516, the silicon extending through theperforations in the bracket to form a tight fit between plunger 112,bracket 1516 and collar 1518. Metal collar 1518 may be simply crimpedonto end 118 of cable 118.

[0084]FIG. 16 illustrates a further alternative method of connectingcable 114 and sleeve 116 to the body fluid flow control device. In theembodiment of FIG. 16, the fluid flow control device has a collar 1600with internal threads 1602. A connector 1604 is used to connect sleeve116 to collar 1600. Connector 1604 has external threads 1606, a centralcollar 1608 and outwardly directed teeth 1610. It should be noted thatconnector 1604 may be the same as connector 1306 illustrated in FIG. 13.This allows for economies in manufacture, as only one type of connectorneed be provided for both ends of the sleeve 116. A metal collar 1612 isused to connect the plunger (not shown in FIG. 16) to end 118 of cable114. An O-ring 1614 may seal between collar 1612 and connector 1604.

[0085] It will be understood that various embodiments of the presentinvention have been disclosed by way of example and that othermodifications and alterations may occur to those skilled in the artwithout departing from the scope and spirit of the appended claims.Thus, the invention described herein extends to all such modificationsand variations as will be apparent to the reader skilled in the art, andalso extends to combinations and subcombinations of the features of thisdescription and the accompanying figures. Although preferred embodimentsof the present invention have been illustrated in the accompanyingfigures and described in the foregoing detailed description, it will beunderstood that the present invention is not limited the embodimentsdisclosed, but is capable of numerous rearrangements, modifications andsubstitutions without departing from the spirit of the present inventionas set forth and defined by the following claims, such as for examplethose embodiments described in non-provisional U.S. patent application,Ser. No. 09/048,823, filed Mar. 26, 1998, which is incorporated hereintoin its entirety by reference.

1. An implantable apparatus for controlling fluid flow within a hostbody comprising: a constricting member for allowing fluid flow within abody canal when in an open position and for reducing fluid flow within abody canal when in a closed position; an actuating member for operatingthe constricting member between said open and closed positions; andcontrol means for operating said actuating member.
 2. The implantableapparatus of claim 1, wherein said constricting member comprises a firstengaging element and a second engaging element for coupling to the firstengaging element to encircle said body canal.
 3. The implantableapparatus of claim 2, wherein at least one of the first engaging elementand the second engaging elements has apertures to allow tissue growththerethrough from and to the surface of the body canal.
 4. Theimplantable apparatus of claim 2, further comprising a locking memberfor locking the first engaging element and second engaging element intoa locked position.
 5. The implantable apparatus of claim 1, wherein saidconstricting member comprises a plunging member moveable such that theplunging member may apply pressure against said body canal to compresssaid body canal into said closed position.
 6. The implantable apparatusof claim 5, wherein said actuating member comprises a link member havinga first and second end.
 7. The implantable apparatus of claim 6, whereinthe first end of the link member is attached to said plunging member andis axially moveable by said control means to move said plunging member.8. The implantable apparatus of claim 6, wherein said actuating membercomprises a housing whereby the second end of the connector extendsslidably through an aperture in the housing and is coupled to anactuator provided in the housing such that movement of the actuatorresults in movement of said plunging member away from the body canal toallow at least some fluid flow therethrough.
 9. The implantableapparatus of claim 6, wherein said actuating member comprises a motoroperatively coupled to the second end of the connector so thatactivation of the motor causes the second end of the link member to beaxially pulled towards the motor resulting in movement of said plungingmember away from the body canal to allow at least some fluid flowtherethrough.
 10. The implantable apparatus of claim 9, furthercomprising a trigger mechanism for activating the motor.
 11. Theimplantable apparatus of claim 6, wherein said actuating membercomprises a magnetic unit coupled to the second end of the connector sothat activation of the magnetic unit causes the second end of theconnector to be axially moved, resulting in movement of said plungingmember away from the body canal to allow at least some fluid flowtherethrough.
 12. The implantable apparatus of claim 11, furthercomprising a manual override system including an additional magnethaving sufficient magnetic force to activate said magnetic unit coupledto said second end of the connector from outside the host body.
 13. Animplantable apparatus for controlling fluid flow within a host bodycomprising: a constricting member for restricting fluid flow within abody canal when in a closed position, and for allowing fluid flow withinthe body canal when in an open position; a control mechanism forcontrolling movement of the constricting member between said open andclosed positions; and a link member linking the constricting member andthe control mechanism such that the constricting member and the controlmechanism are implantable in different parts of the host body.
 14. Theimplantable apparatus of claim 13, wherein said control mechanism isseparable from said link member, whereby said control mechanism may bereplaced without removal of the constricting member or the link memberfrom the host body.
 15. The implantable apparatus of claim 14, wherein:the link member is adapted for actuating said constricting memberbetween said open and closed positions so as to alter fluid flow withinthe body canal; and an actuating member is provided for actuating saidlinking member.
 16. The implantable apparatus of claim 15, wherein theactuating member and the control mechanism are provided in a housingseparate from the constricting member.
 17. The implantable apparatus ofclaim 15, wherein the actuating member comprises a motor.
 18. Theimplantable apparatus of claim 17, further comprising a remotelyoperated trigger mechanism for activating the motor.
 19. The implantableapparatus of claim 17, wherein a coupling for selectively transmittingaxial movement from said motor to said link member is provided betweensaid link member and said motor.
 20. The implantable apparatus of claim19, wherein said coupling comprises a compressible member.
 21. Theimplantable apparatus of claim 20, wherein the compressible member isprovided in a moveable casing, and wherein said link member isoperatively connected to said compressible member, the motor acting tomove said casing, said compressible member acting to move said linkmember.
 22. The implantable apparatus of claim 19, wherein said couplingcomprises magnets.
 23. The implantable apparatus of claim 22, whereinsaid coupling comprises a magnet attached to an end of said link member,and at least one magnet attached to said operating means.
 24. Theimplantable apparatus of claim 23, wherein said at least one magnetattached to said operating means is generally annular, and extendsaround said magnet attached to said link member.
 25. A seal for anelongated link member, said link member extending between an implantableapparatus for implantation in a host body and a control mechanism, thelink member extending through an opening in a housing, wherein the sealcomprises: a tubular membrane having two openings, one opening beingsealed to said housing, the other said opening being sealed to said linkmember such that fluid entering said housing around said link member istrapped by said membrane, said membrane flexing to allow movement of theshaft.
 26. The seal of claim 25, wherein said membrane is sealed to saidlink member by gripping means extending around said membrane and saidshaft.
 27. The seal of claim 26, wherein said gripping means comprises acoil.
 28. The seal of claim 25, wherein said membrane comprises abellows that folds inwardly when the link member is moved axially awayfrom an interior the housing, and expands when the link member is movedaxially into the housing.
 29. The seal of claim 28, wherein said bellowsincludes a reinforcing ring so that folding of said bellows iscontrolled.
 30. An operating mechanism for a constricting member forcontrolling fluid flow in a body canal, the constricting member beingactuable between open and closed positions, the operating mechanismcomprising: an axially moveable link member operatively connected tosaid constricting member for actuating said constricting member;operating means for axially moving said link member; and a coupling forselectively transmitting axial movement from said operating means tosaid link member, said coupling being operatively connected between saidlink member and said operating means.
 31. The operating mechanism ofclaim 30, wherein said coupling comprises a compressible member.
 32. Theoperating mechanism of claim 31, wherein the compressible member isprovided in a moveable casing, and wherein said link member isoperatively connected to said compressible member, the motor acting tomove said casing, said compressible member acting to move said linkmember.
 33. The operating mechanism of claim 30, wherein said couplingcomprises magnets.
 34. The operating mechanism of claim 33, wherein saidcoupling comprises a magnet attached to an end of said link member, andat least one magnet attached to said operating means.
 35. The operatingmechanism of claim 34, wherein said at least one magnet attached to saidoperating means is generally annular, and extends around said magnetattached to said link member.
 36. The operating mechanism of claim 33,further comprising a manual override system including an additionalmagnet having sufficient magnetic force to activate said coupling totransmit axial movement to said link member from outside the host body.37. A method of controlling fluid flow within a host body comprising:implanting a constricting member around a body canal, the constrictingmember reducing fluid flow in the body vessel when in a closed position;implanting a control mechanism in the host body; providing andimplanting a link member between said constricting member and saidcontrol mechanism to allow the control mechanism to control theconstricting member, wherein said control mechanism may be removed fromthe host body and replaced without removal of the constricting memberand the linking member.
 38. The method of claim 37, wherein theconstricting member comprises engaging elements defining an openingtherebetween, the method comprising surrounding the body canal with saidengaging elements so that said body canal extends through said opening.39. The method of claim 37, comprising suturing the engaging elements tothe vessel.
 40. The method of claim 37, further comprising implantingthe control mechanism remote from the body canal.
 41. A remote telemetrysystem for an implantable apparatus, the telemetry system comprising asignaling mechanism capable of sending and receiving signals to and froma control unit implanted in a host body in order to monitor theoperation of the implantable apparatus, the telemetry system beingcapable of altering operating settings of the implantable apparatus. 42.The remote telemetry system of claim 41, wherein said signals areelectromagnetic radiation.
 43. The remote telemetry system of claim 42,wherein said signals are radio waves.
 44. The remote telemetry system ofclaim 41, further comprising sensors to monitor actions of theimplantable apparatus on the host body, and a mechanism to interrogatesaid sensors to provide feedback on the sensed data.
 45. The remotetelemetry system of claim 44, wherein said sensors are capable ofmonitoring pressure exerted by a moveable part of said implantableapparatus on a part of said host body, the feedback on the sensed dataincluding commands to alter the range of movement of said moveable partof said implantable apparatus.
 46. An implantable apparatus forcontrolling fluid flow in a host body, the implantable apparatuscomprising: a constricting mechanism including a reciprocable member forselectively applying pressure to a canal of the host body in order toselectively constrict said canal; a pressure sensor for detecting thepressure applied by said reciprocable member to said canal; and afeedback system for altering movement of said reciprocable member inresponse to the pressure sensed by said pressure sensor in order toprevent damage to said canal.